香港城市大学支春义团队报道了基于超分子晶体的长循环固体锌电池快速单离子导体。相关研究成果于2024年11月4日发表在国际知名学术期刊《德国应用化学》。

由于聚合物链段的缓慢动力学，锌离子电池（ZIBs）中使用的固体聚合物电解质（SPEs）具有较低的离子电导率。由于只支持阳离子的短程运动，导致低离子电导率和Zn²⁺转移（t_Zn²⁺）。锌基超分子晶体（ZMCs）在支持长距离Zn²⁺传输方面具有相当大的潜力；然而，它们在ZIBs中的效率尚未得到探索。

该研究开发了一种由丁二腈（SN）和双（三氟甲基磺酰基）酰亚胺锌（Zn（TFSI）₂）组成的ZMCs，结构式为Zn（TFSI）₂SN₃。ZMC在晶格中具有有序的三维隧道用于离子传导，提供了高的离子电导率（25°C时为6.02×10⁴ S cm^-1，35°C下为3.26×10⁵ S cm^-1）和高的t_Zn²⁺（0.97）。

研究发现，即使在3 mAh cm^-2的高镀层面密度下，具有ZMCs的Zn‖Zn对称电池也具有长期循环稳定性（1200小时）和无枝晶的镀锌/剥离过程。所制备的固态锌电池表现出优异的性能，包括高放电容量（1.52 mAh cm^-2）、长期循环稳定性（70000次循环（7个月）后容量保持率为83.6%）、宽温度适应性（30至50°C）和快速充电能力。

附：英文原文

Title: Supramolecular Crystals based Fast Single Ion Conductor for Long-cycling Solid Zinc Batteries

Author: Ze Chen, Zhaodong Huang, Chenlu Wang, Dedi Li, Qi Xiong, Yanbo Wang, Yue Hou, Yanlei Wang, Ao Chen, Hongyan He, Chunyi Zhi

Issue&Volume: 2024-11-04

Abstract: The solid polymer electrolytes (SPEs) used in Zn-ion batteries (ZIBs) have low ionic conductivity due to the sluggish dynamics of polymer segments. Thus, only short-range movement of cations is supported, leading to low ionic conductivity and Zn2+ transference (tZn2+). Zn-based supramolecular crystals (ZMCs) have considerable potential for supporting long-distance Zn2+ transport; however, their efficiency in ZIBs has not been explored. The present study developed a ZMC consisting of succinonitrile (SN) and zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2), with a structural formula identified as Zn(TFSI)2SN3. The ZMC has ordered three-dimensional tunnels in the crystalline lattices for ion conduction, providing high ionic conductivities (6.02 × 104 S cm1 at 25 °C and 3.26 × 105 S cm1 at 35 °C) and a high tZn2+ (0.97). We demonstrated that a Zn‖Zn symmetrical battery with ZMCs has long-term cycling stability (1200 h) and a dendrite-free Zn plating/stripping process, even at a high plating areal density of 3 mAh cm2. The as-fabricated solid-state Zn battery exhibited excellent performance, including high discharge capacity (1.52 mAh cm2), long-term cycling stability (83.6% capacity retention after 70000 cycles (7 months)), wide temperature adaptability (30 to 50 °C) and fast charging ability.

DOI: 10.1002/anie.202406683

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202406683